It is well known that many people prefer to use inexpensive, disposable paper or plastic bags as a substitute for the conventional cloth or other type reuseable materials for various applications. For example, film and sheet materials made from various plastic polymers, such as polyethylene, polyvinyl chloride, polyesters and the like, and enjoying wide popularity for applications normally reserved for reuseable materials. These materials, even in their film form, are strong, sanitary and relatively inexpensive which lends them well for use as a packaging medium. Consequently, some of the most important uses of plastic film are in the production of wrappers for food, such as sandwich bags, lunch bags, food storage bags and the like. Numerous other important uses have been made of plastic film as, for example, in trash collection, such as wastebasket bags, trash bags and the like, and in dry cleaning stores to cover cleaned suits or dresses. Generally, the latter type plastic bags have been assembled on large dispensing rolls on cores in such a manner that the individual bags are joined to each other along perforated lines that can be relatively easily severed to separate one outermost bag from the roll. However, these rolls are usually large and cumbersome to handle. Recently an improved bag dispenser package was disclosed in pending U.S. application Ser. No. 589,927, titled Bag Dispenser Package, filed June 24, 1975 by J. A. McDonald, which comprises the rolling of separate and discrete bags in sequence into a generally cylindrically shaped coreless roll so that the bags can be removed from the roll one at a time in a sequence starting from the innermost wound bag and proceeding to the outermost wound bag. Although this coreless bag roll assembly is easy to handle and requires a relatively small space for storage, a problem associated with the coreless roll assembly is in providing an apparatus for the automatic and continuous winding of separate bags into coreless rolls.
It is widely known in the art how to roll continuous or separable sheets of material or bags onto cores as disclosed, for example, in U.S. Pat. Nos. 3,387,798, 3,712,554 and 3,844,502. Generally, the leading edge of a continuous sheet or the leading edge of a first sheet is secured to a rotatable core which, upon being rotated, winds the sheet around the core with little or no difficulty. However, to produce a coreless roll assembly, the leading edge cannot be permanently secured to any core or spindle since, in the fully assembled state, the core or spindle has to be removed without disturbing the roll assembly. Although a coreless roll can be assembled by hand, it is the primary object of this invention to provide an apparatus that can automatically assemble discrete sheets, strips or bags into coreless roll assemblies on a continuous basis.
Another object of the invention is to provide an apparatus that can automatically fold a first or leading sheet and then interleave or overlap, a second folded sheet between or superimposed on, respectively, the trailing end portion of the first sheet and so on in sequence, followed by rolling the strand of sheets so arranged into a coreless roll assembly.
Another object of the invention is to provide an apparatus for producing coreless roll assemblies of separable and sequentially wound sheets or bags which employs a winding assembly composed of two spaced-apart axially aligned and axially translatable spindles, each having ports in its circumferential surface adapted for coupling to a gas supply and/or vacuum means, and flexible belt guide means cooperating with the spindles by substantially circumscribing and being urged against the spindles or sheet wound spindles during the winding mode of operation so as to effectively guide and advance the first and successive sheets about said spindles.
Another object of the invention is to provide an apparatus for producing coreless roll assemblies of separable and sequentially wound sheets or bags which employs a pair of driven belt means spaced apart to define a restrictive passage composed of a pair of side walls made up of belt segments of the respective belt means which, in the operation mode of the apparatus, will guide and advance folded strips from the folding station to a winding station of the apparatus.
Another object of the invention is to provide a process for forming a strand of separable folded sheets into a self-sustaining coreless roll assembly.
The foregoing and additional objects will become more fully apparent from the following description and the accompanying drawings.